The Presidential Policy Directive, PPD-21, released on February 12 supersedes the 2003 Homeland Security Presidential Directive (PPD-7). The intent of the Directive is to provide an “all hazards” approach to the risks facing critical infrastructure.

PPD-21 directs and encourages the participation of critical infrastructure owners and operators.

Department of Homeland Security (DHS)
The DHS has primary responsible for maintaining national critical infrastructure centers for situational awareness, coordinating Federal Government response to significant cyber or physical incidents and reporting annually on the status.

DHS will coordinate with sector specific agencies to:

Identify and prioritize critical infrastructure

Provide analysis, expertise and other technical assistance to critical infrastructure

Conduct comprehensive assessments of vulnerabilities

Map and sort critical infrastructure.

DHS will support the law enforcement agencies to investigate and prosecute threats.

In addition, DHS will run two national critical infrastructure centers. One will focus on cyber threats and the other will be on physical threats. They will be integrated and will perform analysis and situational awareness.Sector Specific Agencies (SSAs)

The following are the SSAs:

Chemical : Department of Homeland Security

Commercial Facilities : Department of Homeland Security

Communications : Department of Homeland Security

Critical Manufacturing : Department of Homeland Security

Dams : Department of Homeland Security

Defense Industrial Base : Department of Defense

Emergency Services : Department of Homeland Security

Energy : Department of Energy

Financial Services : Department of the Treasury

Food and Agriculture : U.S. Department of Agriculture & Department of Health and Human Services